Beyond fluorescence-guided resection: 5-ALA-based glioblastoma therapies.

Glioblastoma is the most common primary malignant brain tumor. Despite advances in multimodal concepts over the last decades, prognosis remains poor. Treatment of patients with glioblastoma remains a considerable challenge due to the infiltrative nature of the tumor, rapid growth rates, and tumor heterogeneity. Standard therapy consists of maximally safe microsurgical resection followed by adjuvant radio- and chemotherapy with temozolomide. In recent years, local therapies have been extensively investigated in experimental as well as translational levels. External stimuli-responsive therapies such as Photodynamic Therapy (PDT), Sonodynamic Therapy (SDT) and Radiodynamic Therapy (RDT) can induce cell death mechanisms via generation of reactive oxygen species (ROS) after administration of five-aminolevulinic acid (5-ALA), which induces the formation of sensitizing porphyrins within tumor tissue. Preliminary data from clinical trials are available. The aim of this review is to summarize the status of such therapeutic approaches as an adjunct to current standard therapy in glioblastoma.

Effect of photodynamic therapy with 5-aminolevulinic acid and EDTA-2Na against mixed infection of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa.

BACKGROUND: The increasing abundance of drug-resistant bacteria is a global threat. Photodynamic therapy is an entirely new, non-invasive method for treating infections caused by antibiotic-resistant strains. We previously described the bactericidal effect of photodynamic therapy on infections caused by a single type of bacterium. We showed that gram-positive and gram-negative bacteria could be killed with 5-aminolevulic acid and 410 nm light, respectively. However, clinically, mixed infections are common and difficult to treat. OBJECTIVE: We investigated the bactericidal effects of photodynamic therapy on mixed infections of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. METHODS: We compared bacterial growth with and without photodynamic therapy in vitro. Then, in vivo, we studied mixed infections in a mouse skin ulcer model. We evaluated the rates of ulcer area reduction and transitions to healing in treated and untreated mice. In addition, a comparison was made between PDT and existing topical drugs. RESULTS: We found that photodynamic therapy markedly reduced the growth of both methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, in culture, and it reduced the skin ulcer areas in mice. PDT was also more effective than existing topical medicines. CONCLUSION: This study showed that photodynamic therapy had antibacterial effects against a mixed infection of gram-positive and gram-negative bacteria, and it promoted skin ulcer healing. These results suggested that photodynamic therapy could be effective in both single- and mixed-bacterial infections.

Efficacy of photodynamic therapy using ALAHCl in gel with a lipid nanoemulsion and MALHCl in cream in superficial basal cell carcinoma.

INTRODUCTION AND OBJECTIVE: Photodynamic therapy (PDT) is a therapeutic option for low-risk basal cell carcinoma (BCC). The aim of the study was to assess the efficacy of topical PDT in the treatment of superficial BCC (sBCC) using two different photosensitizers: aminolevulinic acid hydrochloride (ALA-HCl) in a gel formulation with a lipid nanoemulsion (ALA-HCl in gel) and ALA methyl ester hydrochloride (MAL-HCl) in a cream formulation (MAL-HCl in cream). MATERIAL AND METHODS: 21 patients were treated twice with a one week interval between treatments. The formulations were applied onto lesions: 10 patients were treated with MAL-HCl in cream, and 11 with ALA-HCl in gel. After three hours of incubation and removing the preparations, fluorescence was assessed. The skin areas were then irradiated with red light 630 ± 5 nm. RESULTS: At the follow-up visit 12 weeks after the second treatment, complete clinical remission was found in 82% after ALA-HCl in gel and in 80% after MAL-HCl in cream. An excellent cosmetic result was found in 96% of patients after MALHCl in cream and in 100% after ALA-HCl in gel. Faster skin healing and less post-inflammatory hyperpigmentation during follow-up visits was observed after treatment with ALA-HCl in gel. CONCLUSIONS: Both formulations - ALA-HCl in gel and MAL-HCl in cream - were highly effective photosensitisers for PDT. The advantage of ALA-HCl in a gel formulation with a lipid nanoemulsion was faster skin healing, resulting in better cosmetic results.

Comparative response to PDT with methyl-aminolevulinate and temoporfin in cutaneous and oral squamous cell carcinoma cells.

Cutaneous and Head and Neck squamous cell carcinoma (CSCC, HNSCC) are among the most prevalent cancers. Both types of cancer can be treated with photodynamic therapy (PDT) by using the photosensitizer Temoporfin in HNSCC and the prodrug methyl-aminolevulinate (MAL) in CSCC. However, PDT is not always effective. Therefore, it is mandatory to correctly approach the therapy according to the characteristics of the tumour cells. For this reason, we have used cell lines of CSCC (A431 and SCC13) and HNSCC (HN5 and SCC9). The results obtained indicated that the better response to MAL-PDT was related to its localization in the plasma membrane (A431 and HN5 cells). However, with Temoporfin all cell lines showed lysosome localization, even the most sensitive ones (HN5). The expression of mesenchymal markers and migratory capacity was greater in HNSCC lines compared to CSCC, but no correlation with PDT response was observed. The translocation to the nucleus of ß-catenin and GSK3ß and the activation of NF-κß is related to the poor response to PDT in the HNSCC lines. Therefore, we propose that intracellular localization of GSK3ß could be a good marker of response to PDT in HNSCC. Although the molecular mechanism of response to PDT needs further elucidation, this work shows that the most MAL-resistant line of CSCC is more sensitive to Temoporfin.

New, simplified versus standard photodynamic therapy (PDT) regimen for superficial and nodular basal cell carcinoma (BCC): A single-blind, non-inferiority, randomised controlled multicentre study.

BACKGROUND: Topical photodynamic therapy (PDT) is an approved and widely used treatment for low-risk basal cell carcinoma (BCC), comprising two sessions with an interval of 1 week. Simplification of the treatment course can be cost-effective, easier to organize, and cause less discomfort for the patients. METHODS AND FINDINGS: We performed an investigator-initiated, single-blind, non-inferiority, randomized controlled multicentre study with the objective of investigating whether a simpler and more flexible PDT regimen was not >10% less effective than the standard double PDT in the treatment of primary, superficial, and nodular ≤2 mm-thick BCC and evaluate the cosmetic outcome. With a non-inferiority margin of 0.1 and an expected probability complete response of 0.85, 190 tumours were required in each group. Histologically verified BCCs from seven centres in Norway were randomly assigned (1:1) to either receive a new regimen of single PDT with one possible re-treatment of non-complete responding tumours, or the standard regimen. The primary endpoint was the number of tumours with complete response or treatment failure at 36 months of follow-up, assessed by investigators blinded to the treatment regimen. Intention-to-treat and per-protocol analyses were performed. The cosmetic outcome was recorded. The study was registered with ClinicalTrials.gov, NCT-01482104, and EudraCT, 2011-004797-28. A total of 402 BCCs in 246 patients were included; 209 tumours assigned to the new and 193 to the standard regimen. After 36 months, there were 61 treatment failures with the new and 34 failures with the standard regimen. Complete response rate was 69.5% in the new and 81.1% in the standard treatment group. The difference was 11.6% (upper 97.5% CI 20.3), i.e. > than the non-inferiority margin of 10%. Cosmetic outcomes were excellent or good in 92% and 89% following the new and standard regimens, respectively. CONCLUSIONS: Single PDT with possible re-treatment of primary, superficial, and nodular ≤ 2-mm-thick BCC was significantly less effective than the approved standard double treatment. The cosmetic outcome was favorable and comparable between the two treatment groups.

Evaluation of the potential of Delta-aminolevulinic acid for simultaneous detection of bioburden and anti-microbial photodynamic therapy of MRSA infected wounds in Swiss albino mice.

BACKGROUND: The dramatic increase of drug-resistant bacteria necessitates urgent development of platforms to simultaneously detect and inactivate bacteria causing wound infections, but are confronted with various challenges. Delta amino levulinic acid (ALA) induced protoporphyrin IX (PpIX) can be a promising modality for simultaneous bioburden diagnostics and therapeutics. Herein, we report utility of ALA induced protoporphyrin (PpIX) based simultaneous bioburden detection, photoinactivation and therapeutic outcome assessment in methicillin resistant Staphylococcus aureus (MRSA) infected wounds of mice. METHODS: MRSA infected wounds treated with 10% ALA were imaged with help of a blue LED (∼405 nm) based, USB powered, hand held device integrated with a modular graphic user interface (GUI). Effect of ALA application time, bacteria load, post bacteria application time points on wound fluorescence studied. PpIX fluorescence observed after excitation with blue LEDs was used to detect bioburden, start red light mediated antimicrobial photodynamic therapy (aPDT), determine aPDT effectiveness and assess selectivity of the approach. RESULTS: ALA-PpIX fluorescence of wound bed discriminates infected from uninfected wounds and detects clinically relevant load. While wound fluorescence pattern changes as a function of ALA incubation and post infection time, intra-wound inhomogeneity in fluorescence correlates with the Gram staining data on presence of biofilms foci. Lack of red fluorescence from wound granulation tissue treated with ALA suggests selectivity of the approach. Further, significant reduction (∼50%) in red fluorescence, quantified using the GUI, relates well with bacteria load reduction observed post topical aPDT. CONCLUSION: The potential of ALA induced PpIX for simultaneous detection of bioburden, photodynamic inactivation and "florescence-guided aPDT assessment" is demonstrated in MRSA infected wounds of mice.

Potential therapeutic efficacy of photodynamic therapy on female hormonal-dependent cancers in a hormonal simulated microenvironment.

BACKGROUND: Photodynamic Therapy (PDT) is a clinically approved cancer treatment. Sex hormones, the key drivers for the development of female hormonal dependent cancers, might affect cancer treatment. There are seldom studies to evaluate the effect of sex hormones mimicked the menstrual cycle on the PDT mediated by prodrug 5-aminolevulinic acid (ALA) and its ester derivatives to the hormonal dependent cancers. AIMS: To evaluate the efficacy of sex hormones on Hexyl-ALA-PDT in hormonal dependent cancers and the effect of the sex hormones on heme biosynthetic pathway. METHODS: Cell culture system that mimicked the fluctuation of sex hormones 17ß-estradiol (E2) and progesterone (PG) in the menstrual cycle was developed. Two pairs of hormonal-independent and hormonal dependent uterine sarcoma and breast cancer cell lines were used as cell models. Hexyl-ALA induced PpIX production and intracellular localization were examined. Key enzymes for PpIX synthesis were analysed. Hexyl-ALA-PDT mediated phototoxicity was evaluated. RESULTS: The PpIX generation was increased in the hormonal-dependent cells (28-50 %) when cultured in the hormonal microenvironment with long incubation of Hexyl-ALA for 15 and 24 h compared to that cultured without hormones; whereas only slight difference in PpIX generation in their hormonal-independent counterpart. The PpIX generation was in a time-dependent manner. The CPOX, PPOX and FECH expressions were significantly enhanced by Hexyl-ALA-PDT in uterine sarcoma cells in hormonal microenvironment. Hexyl-ALA-PDT triggered significant increase of PPOX expression in breast cancer cells in hormonal microenvironment. The Hexyl-ALA-PDT phototoxicity was enhanced by 18-40 % in cells cultured in the hormonal system in a dose-dependent manner. CONCLUSION: The PpIX generation and the efficacy of Hexyl-ALA-PDT in both uterine sarcoma and breast cancer cells was significantly enhanced by the sex hormones via cultured in the hormonal microenvironment.

The Effect of Photodynamic Therapy Using 5-Aminolevulinic Acid in Bone and Soft Tissue Sarcoma Cells.

BACKGROUND/AIM: 5-Aminolevulinic acid (5-ALA) is a natural amino acid and a precursor of protoporphyrin IX (PpIX). Following light irradiation, the PpIX generates reactive oxygen species (ROS) in the presence of oxygen. Increased ROS levels can cause apoptotic cell death and necrosis of targeted cancer cells. This study examined whether photodynamic therapy using 5ALA (5-ALA PDT) could be used as a potential adjuvant therapy for bone and soft tissue sarcomas. MATERIALS AND METHODS: The human osteosarcoma (143B), mouse osteosarcoma (LM8), human fibrosarcoma cell (HT1080) cell lines were used. In vitro, cultured cells were exposed to 5-ALA at various concentrations followed by strobe scope light irradiation for 10 min as 5-ALA PDT. Cell viability was then measured. In vivo, each tumor cell line was inoculated subcutaneously into the backs of mice. In the 5-ALA PDT group, 5-ALA (250 mg/kg) was administered intraperitoneally followed by light irradiation. Change in tumor volume by 5-ALA PDT were primarily evaluated. RESULTS: In vitro, treatment of sarcoma cells with 100 and 200 µg/ml 5-ALA PDT significantly inhibited cell proliferation at 24 and 48 h compared with the group treated with 0 and 10 µg/ml 5-ALA PDT. In vivo, in all cell lines, a significant inhibition of the tumor volume was observed in the 5-ALA-PDT group as compared to that in control, strobe scope light, and 5-ALA groups. CONCLUSION: 5-ALA PDT effectively inhibited proliferation of bone and soft tissue sarcoma cell lines. Further in vivo research using other subtypes of bone and soft tissue sarcoma is warranted to confirm the applicability in the clinical setting.

Clinical evaluation of photodynamic therapy for oral leukoplakia: a retrospective study of 50 patients.

BACKGROUND: Topical photodynamic therapy (PDT) has demonstrated encouraging results in the treatment of oral leukoplakia (OLK). However, data on the clinical efficacy of PDT in Chinese patients with OLK are still limited. METHODS: Fifty patients diagnosed with OLK were enrolled, including patients with various dysplastic tissues. All patients received topical PDT with 5-aminolevulinic acid (5-ALA) as a photosensitizer. Clinical efficacy was evaluated 4 weeks after treatment. Follow-up was performed every 3 months during the first year and every 6 months during the second year. RESULTS: The overall response rate was 68% (34/50): 12% (n = 6) complete and 56% (n = 28) partial responses. Aneuploidy was reduced in the patients with dysplastic lesions. Oral pain and local ulcers developed in 52% of the patients (n = 26). Patients with a long history of OLK including hyperplasia and dysplastic lesions, as well as those with non-homogenous lesions, were more likely to develop pain and ulcer. During follow-up, the recurrence rate of hyperplasia and dysplastic lesions was 32% (n = 16) and the malignant transformation rate of dysplastic lesions was 4% (n = 2). Lesions on the buccal mucosa were associated with recurrence (P = 0.044; OR: 0.108, 95% CI: 0.013-0.915). CONCLUSION: Topical 5-ALA-mediated PDT is an effective treatment for OLK, particularly for homogenous leukoplakia, with few side effects. The buccal mucosa may be a protective factor that can reduce recurrence.

Topical 5-aminolevulinic acid (ALA)-photodynamic therapy (PDT) for lichen sclerosus of face: case report and literature review.

Lichen sclerosus (LS) is a chronic inflammatory dermatosis typical of the genital region, with rare involvement of extragenital areas and particularly the face. LS therapeutic management is challenging, and common therapies including topical and systemic corticosteroids, topical calcineurin inhibitors, surgery are often ineffective. Herein, we present a case of LS occurred in a 36-year-old girl with facial involvement resistant to therapy with systemic corticosteroids and topical tacrolimus. Considering the involvement of a sensitive area, the young age of the patient, and the consistent clinical experience in using photodynamic therapy for the treatment of facial skin disease, we started a treatment with topical 5-aminolevulinic acid (ALA)-photodynamic therapy (PDT) with a dosage of 37 J/cm2 once a month. We compared our case with eight other facial LS patients from the literature and treated differently.

Basal cell carcinoma arising within nevus sebaceous on the right scalp in a 55-year-old male: A case report and review of literature.

We report here a case of nevus sebaceous in a 55-year-old male, who presented with a 50-year history of an asymptomatic swelling in his right scalp. The solitary, yellowish, expansile plaque over the scalp gradually became lobulated and turned dark-pigmented with spontaneous bleeding, itching discomfort, and occasional ulceration after scratching. The male's clinical presentation and histopathological findings were compatible with basal cell carcinoma arising in nevus sebaceous. At present, 5-aminolevulinic acid photodynamic therapy (ALA-PDT) emerges as a novel treatment modality which has proved safe and effective. In this case, three sessions of photodynamic therapy in combination with surgical excision were performed, leaving mild pigmentation within 3 weeks. The patient showed good cosmetic outcome, minimal scarring on the right scalp without further complications, disease recurrence or metastasis after ALA-PDT within six months.

Photodynamic therapy for cutaneous inflammatory pseudotumour: A case report.

Inflammatory pseudotumour (IP) is a rare proliferative disease characterized by a dense infiltrate of plasma cells, lymphocytes, eosinophils and neutrophils in the fibrous stroma. It primarily affects the lungs of pediatric patients or young adults. Cutaneous IP is an extremely rare condition, with limited documentation in the English literature. In this case report, we presented an unusual instance of a 62-year-old male endured recalcitrant cutaneous IP for 8 years and exhibited poor response to topical glucocorticoid therapy, as well as intralesional injections of pingyangmycin and/or corticosteroid. Notably, after undergoing four sessions of 5-aminolevulinic acid photodynamic therapy (ALA-PDT), the patient experienced a significant reduction in erythema and nodules. This observation suggests that ALA-PDT may represent a promising and safe treatment option for cutaneous IP.

Successful application of aminolevulinic acid/photodynamic therapy in the treatment of giant condyloma acuminatum in an 87-year-old patient.

Condyloma acuminatum is a common sexually transmitted disease caused by human papillomavirus infection and is a benign hyperplastic lesion of the genital and perianal areas. The principle of its treatment is to remove the visible warts as much as possible and to prevent recurrence. Traditional treatment methods of condyloma acuminatum, such as CO2 laser, liquid nitrogen freezing, surgery, and topical medications, can remove warts. However, these methods have disadvantages such as pain, high recurrence rates, long treatment cycles, and scarring. Aminolevulinic acid/photodynamic therapy (ALA-PDT), a safe and effective method, has been widely used to treat condyloma acuminatum in recent years. Condyloma acuminatum occurs relatively rarely in elderly patients, in whom treatment is difficult owing to poorer physiological function. We successfully treated an 87-year-old patient with a giant condyloma acuminatum of the glans penis using six sessions of ALA-PDT at 7-day intervals and obtained satisfactory results. No recurrence was observed during a 6-month follow-up. Therefore, ALA-PDT is worth popularizing in clinical practice.

Efficacy and safety of fractional carbon dioxide laser followed by 5-aminolevulinic acid photodynamic therapy for keloids.

BACKGROUND: Keloids are aggressive fibroproliferative disorders that cause aesthetic and functional damage. Photodynamic therapy (PDT) has shown promise as a novel treatment for keloids. However, the limited penetration of 5-aminolevulinic acid (ALA) and unsatisfactory outcomes in dense scars hinder its effectiveness as a monotherapy. The objective of this study is to assess the efficacy and safety of fractional CO2 laser followed by 5-ALA PDT for keloids. METHODS: A total of 12 patients with keloid were included in our study. Each lesion was pretreated by fractional CO2 laser with 26-28 W to create microthermal zones. After topical application of 5-ALA solution, an irradiation of 635 nm red light with 120 J/cm2 was performed. The treatment was repeated at least every 2 weeks. Efficacy and safety were evaluated using the Vancouver Scar Scale (VSS), the Visual Analogue Scale (VAS) for keloid-related symptoms and documentation of postoperative complications. Statistical analysis was performed to compare VSS and keloid-related symptom VAS scores of the baseline and final treatment sessions. RESULTS: The final treatment resulted in a statistically significant decrease in all parameters of VSS and VAS for pruritus and pain compared to the baseline. Except for postoperative hyperpigmentation, no infections, scar aggravation, or recurrence were observed during at least 6 months of follow-up. Overall, patients expressed a high level of satisfaction with the treatment outcome. CONCLUSIONS: Fractional CO2 laser followed by 5-ALA PDT is a promising method for treating keloids. However, its synergetic effects need to be validated through clinical trials involving larger patient cohorts.

Photodynamic therapy combined with CO2 laser for the treatment of seborrheic keratosis in the auricle: A case report.

Seborrheic keratosis(SK) is a very common skin tumor which is mostly frequently observed in the trunck, head, neck. SK in the auricle is rare and this condition should be excluded the possibility of malignancy by pathologic diagnosis. We report a case of 66-year-old man who presented with a brownish, papillomatous, verrucous mass in the auricle for the past seven years, which began to growing faster during the previous year. Dermoscopy and histopathological examination were performed and the patient was diagnosed with SK. He was treated with the carbon dioxide(CO2) laser and aminolevulinate photodynamic therapy (ALA-PDT). The CO2 laser was used for the removal of the thick hypertrophic lesions and to enhance the transdermal absorption efficiency of ALA. A 20% ALA cream(118 mg/cm2) was applied to his lesion and sealed for 3 h without light, followed by irradiation with 630-nm LED light (96 J/cm2, 80 mw/cm2). We use fluorescent diagnosis with aminolevulinic acid to define the tumor margins at the first session of ALA-PDT. After 4 sessions of ALA-PDT, the lesion was completely removed and did not recur. Therefore, we consider that ALA-PDT combined with CO2 laser is a safe and effective choice for the treatment of seborrheic keratosis in the auricle.

The efficacy of 5-aminolevulinic acid photodynamic therapy for pediatric vulvar lichen sclerosus.

BACKGROUND: Prepubertal girls are one of the vulnerable populations of vulvar lichen sclerosus (VLS), which results in a decreased quality of life and increases risk of vulvar cancer. But the therapeutic effects of traditional topical remedies are unsatisfactory in some pediatric patients. 5-Aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective treatment for refractory VLS patients, but no study has been conducted in child patients. METHODS: The patients included in this study underwent three sessions of ALA-PDT at 2-week intervals. All patients were evaluated for objective clinical appearances and subjective symptoms quantitatively. Statistical analysis comparing parameters at baseline and after three-time ALA-PDT was performed. RESULTS: A total of seven VLS girl patients were included in this study. Both primary objective appearances (lesion size and depigmentation) and subjective symptoms (itching and burning pain) were improved remarkably after the third treatment. Besides, adverse effects, mainly as pain and post-treatment edema, were mild and could be tolerated. CONCLUSIONS: ALA-PDT is an effective and safe therapeutic option for VLS girl patients. Compared with adult patients, the symptoms resolved more quickly in child patients.

Photodynamic therapy for refractory erosive oral lichen planus: a case series study.

Oral lichen planus is a chronic inflammatory disease that occurs on the oral mucosa and is an oral potentially malignant disease. Treatment of oral lichen planus aims to promote healing of the erosion, relieve pain, reduce recurrence of the erosion, and prevent canceration. Corticosteroids are the first line of treatment for oral lichen planus. Refractory oral lichen planus is a clinical classification of oral lichen planus that has not responded to corticosteroid treatment for more than 2 months. Topical 5-aminolevulinic acid-mediated photodynamic therapy is an innovative and effective treatment for potentially malignant oral diseases and has been reported as an alternative treatment to conventional therapies for oral lichen planus. On this basis, we report 3 cases of refractory erosive oral lichen planus in which persistent erosive lesions healed after topical application of 5-aminolevulinic acid-mediated photodynamic therapy without any adverse effects or any signs of recurrence. Topical 5-aminolevulinic acid-mediated photodynamic therapy will become an effective clinical treatment for refractory erosive oral lichen planus.

Combination of vitamin D and photodynamic therapy enhances immune responses in murine models of squamous cell skin cancer.

Improved treatment outcomes for non-melanoma skin cancers can be achieved if Vitamin D (Vit D) is used as a neoadjuvant prior to photodynamic therapy (PDT). However, the mechanisms for this effect are unclear. Vit D elevates protoporphyrin (PpIX) levels within tumor cells, but also exerts immune-modulatory effects. Here, two murine models, UVB-induced actinic keratoses (AK) and human squamous cell carcinoma (A431) xenografts, were used to analyze the time course of local and systemic immune responses after PDT ± Vit D. Fluorescence immunohistochemistry of tissues and flow analysis (FACS) of blood were employed. In tissue, damage-associated molecular patterns (DAMPs) were increased, and infiltration of neutrophils (Ly6G+), macrophages (F4/80+), and dendritic cells (CD11c+) were observed. In most cases, Vit D alone or PDT alone increased cell recruitment, but Vit D + PDT showed even greater recruitment effects. Similarly for T cells, increased infiltration of total (CD3+), cytotoxic (CD8+) and regulatory (FoxP3+) T-cells was observed after Vit D or PDT, but the increase was even greater with the combination. FACS analysis revealed a variety of interesting changes in circulating immune cell levels. In particular, neutrophils decreased in the blood after Vit D, consistent with migration of neutrophils into AK lesions. Levels of cells expressing the PD-1+ checkpoint receptor were reduced in AKs following Vit D, potentially counteracting PD-1+ elevations seen after PDT alone. In summary, Vit D and ALA-PDT, two treatments with individual immunogenic effects, may be advantageous in combination to improve treatment efficacy and management of AK in the dermatology clinic.

Photodynamic therapy for severe acne.

Acne is an inflammatory cutaneous disease affecting the pilosebaceous unit and hair follicles on the face, neck, back, and chest, with a typical onset in adolescence and, in some cases, persisting into adulthood. Systemic treatments with antibiotics or isotretinoin present many limitations, like antimicrobial resistance phenomena and teratogenicity, which appear more relevant in the pediatric population, both for the treatment-related risks and for the reticence of the parents. Photodynamic therapy (PDT) has already shown encouraging results in the treatment of acne in adult patients, with good aesthetic results compared to other therapies and few side effects. However, its use is still not standardized in the pediatric population. On this topic, we report our experience with PDT in a young patient affected by dorsal acne. After five sessions of ALA-PDT at monthly intervals, a remarkable improvement of the lesions was observed, with the healing of the inflamed nodules and pustules, resolution of the painful symptoms, and an acceptable cosmetic outcome. Our case is paradigmatic of the potentiality of PDT to treat difficult and resistant-to-treatment lesions. Despite being time-consuming, this procedure has been demonstrated to be safe and well-tolerated. Lastly, the therapy is also well accepted by parents, due to its minimal invasiveness and mild side effects, compared to the other therapeutic options.